Bacterial microbiota shifts in vacuum-packed beef during storage at different temperatures: Impacts on blown pack spoilage

We aimed to evaluate the bacterial growth and diversity in vacuum-packed beef bags stored at different temperatures and to monitor blown-pack spoilage. We used culture-based methods and high-throughput sequencing to study the development of the main bacterial groups naturally present in beef stored at 4 and 15 degrees C for 28 days. The growth of sulfite-reducing clostridium (SRC) was impaired in beef bags stored at 4 degrees C; significant differences among SRC counts were observed in beef bags stored at 4 and 15 degrees C on days 14, 21, and 28 (P = 0.001). Blown pack was observed in most beef bags stored at 15 degrees C, from day 14 to day 28, but not in beef bags stored at 4 degrees C. A storage temperature of 4 degrees C was able to maintain a stable bacterial microbiota (most prevalent: Photobacterium, Hafnia-Obesumbacterium, and Lactococcus). Remarkable changes in microbial abundance occurred at 15 degrees C from day 14 to day 28, with a predominance of strict anaerobes (Bacteroides) and the presence of Clostridium spp. The relative frequencies of strict anaerobes and Clostridium were statistically higher in the beef bags stored at 15 degrees C (P < 0.001 and P = 0.004, respectively). The temperature influenced the microbial counts and relative abundance of spoilage bacteria, leading to blown pack spoilage.